To: "John H."
Subject: Re: due to some kind of interference, monitor display is "shaking"
References:
<[email protected]>
"John H." writes:
> ok, the thing i bought from radioshack is
> 75-ohm tv/vcr/fm interference filter
> ????
You mean this product
http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&product%5Fid=15-579
Eht web page says:
"Cuts CB/Ham interference. This 54-900MHz high-pass filter installs
inline at the 75-ohm (F connector) input jack on TV or VCR."
According the documentation this device is designed to be
a high-pass filter. This kind of high pass filter if the
filtering is all this does is not do what is wanted.
We want to cut the current flowing on the cable shield with
an antenna cable isolator without too much affecting the
signal inside cable.
This radioshack device is according to the documentation
designed to affect the signal inside cable (high pass filter it)
and does not tell anything what it does with the shield currents
(propably does not do anything).
If you have a multimeter measure with ohms range if there is an
electricl connection between the input and output connector.
If you measure low resistance (few ohms or less), then it is
sure that this kind of filter does not do anythign to ground loop
problem! If you measure practically infinite resistance between
the inout and output connector shields, then this device is
type of isolator we want.
I have used successfully the following pretty similar looking
(propably made by same manufacturer) device that ise designed
as antenna isolator to solve ground loop problems.
Jebsee EU-634
http://www.vekoy.com/product_info.php?manufacturers_id=84&products_id=3568&osCsid=15511701308b91c625771bceaea1c0bd
--
Tomi Engdahl (http://www.iki.fi/then/)
Take a look at my electronics web links and documents at
http://www.epanorama.net/